1. Field of the Invention
The present invention relates to a camera provided with a battery chamber for a built-in battery and a battery cover for covering the battery chamber.
2. Description of the Prior Art
Quite recently, cameras have become more and more automatic, and many cameras are provided with such efficiency features as automatic winding and rewinding, automatic focusing lens driving, and so on. Accordingly, the capacity of a power source battery becomes necessarily large. The increase in the capacity of the power source battery results in also an increase in the loading space thereof, so that places where the battery may be loaded are limited. Namely, the battery loading space is provided, generally, in the grip or the bottom of the camera. However, the grip is directly connected to an operation such as holding and so on, so that there takes place the restriction of the appearance and the form, and thus it is difficult to secure the desired loading space for the power source battery. On the other hand, in the bottom, four power source batteries can be loaded. However, the height of the camera as a whole becomes large, so that it goes without saying that it is necessary to make the camera compact and compress the mechanical parts.
Hereinafter, a camera in which a power source battery is loaded in the bottom of the camera is mentioned. Because, generally, four power source batteries are loaded, a battery cover with a large area is required. Because of the recent tendency to reduce weight and increase freedom of design, the battery cover is, in many cases, made of a plastic. Further, as to the camera body, for example, of a single lens reflex camera, the whole body is made of a metal, or at least a tripod mounting part is metal-inserted, in order to obtain the satisfactory strength. In the camera constructed as mentioned above, there are many places, such as an accessory shoe, a remote control terminal and so on, which may be connected from the outside of the camera, and which are connected to a metal part of the camera body to be on the same electric potential as the metal part. The reason for this is that the body of the camera is, generally, set at the ground level due to the circuit construction.
It has been experimentally found that there is a possibility that, in a case where such a camera is put on an electrostatically charged carpet or the like and a human body touches an exposed part of the camera such as an accessory shoe, the metal part of the camera body is electrically charged. When the camera is charged so much, a discharge takes place between the camera body and the carpet (via the power source battery arranged in the bottom or the like), so that a large voltage fluctuation occurs and, consequently, the misoperation or the breakage of a central processing unit (CPU) for controlling various signals takes place.
On the other hand, in the case of such a camera which requires a battery cover with a large area, an operation cover such as a battery cover is, generally, provided with hinges so as to prevent from the separation of the hinges from the camera body. Where such a large battery cover as mentioned above is required, too much load is often applied to the hinges at the time when the power source battery is loaded or unloaded. Accordingly, the hinges must be strong enough. Furthermore, because it is necessary to make the opening angle of the battery cover large enough not so as to disturb the loading and unloading operation of the power source battery, the hinges must be arranged at the position distant from the loading and unloading path of the power source battery. In order to satisfy the above-mentioned conditions, it is necessary to arrange strong hinges which requires a large space, at the position distant from (outside of) the loading and unloading path of the power source battery. It is disadvantageous for realizing a compact camera, especially, when the battery cover is formed of a plastic (because the wall thickness should be large in order to obtain strength).
It has been proposed to adopt a detachable battery cover which is not provided with hinges. However, generally speaking, while there is a danger of losing detachable parts, in the present case, the battery cover is large, so that there is no problem. However, in the case of a simply detachable battery cover, there is a possibility that the battery cover may be unexpectedly dropped at the time of the detaching operation, whereby, depending upon the environment, the recovery is impossible, so that such a problematic point should absolutely be avoided.